Spanner wrench



Nov. 15, 1955 L. SCHWAIGER 2,723,581

SPANNER WRENCH Filed Nov. 13, 1952 ATTORNEY hired States Patent n ice2,723,581 Rntented Nov. 15, 1955 SPANNER WRENCH Leo.Schwaiger, Cullman,Ala. Application November 13, 1952, Serial No. 320,210 4 Claims. (Cl.8190) The present invention pertains to wrenches, and more particularlyto special dcuble-endedwrenches adapted for use with special nuts of acharacter hereinafter described.

The Wrench which constitutes the subject matter of the present inventionis particularly useful in situations where the range of angular movementof the wrench is restricted by the presence of mechanical obstructions.

An object of the invention is the provision of a double ended wrenchwhich is adapted for use with regularly shaped nut having a central.axis of symmetry. The periphery of the nut has a plurality of regularlyspaced outwardly opening three-sided recesses formed therein. Eachrecess includes two opposed flat convergent sides the planes of which,if outwardly extended, would intersect each other in a line ofintersection which lies in a plane passing through the central axis ofsymmetry of the nut and which also passes through the center of therecess. This line of intersection is located radially outwardly beyondthe periphery of the nut and the angle .of intersection of the extendedplanes of the convergent sides is preferably greater than 30 in order toprovide inner corners in each recess for engagement by a tooth portionof the wrench. The third or inner side of each nut recess extendsbetween the inner ends of the convergent flat sides and is of convexlycurved shape, the center of curvature being located at the axis ofsymmetry of the nut.

The external peripheral configuration of the said nut may be eithercircular or hexagonal, or may take the shape of any desired regularpolygon.

Another object of the invention is to provide a wrench which isadaptable for use with a variety of nuts, the said nuts beingcharacterized by the provision of regularly spaced outwardly openingthree-sided peripheral recesses as described above.

Generally, the wrench which forms the subject matter of the presentinvention is preferably a double-ended wrench, although it may be asingle-ended wrench, if desired. The wrench is characterized by a toothwhich engages in a corner of the nut recess and a cooperating surfacewhich holds the tooth positively engaged in the corner during theturning of the nut by the wrench.

In a double-ended wrench in accordance with the invention, one nutengaging portion at one end of the wrench has an outwardly openingrecess formed therein which is arranged to embrace a peripheral portionof the nut which extends between two adjacent ones of the nut recesses.The corner engaging tooth is disposed at one end of the wrench recessand the surface which holds the tooth engaged in the corner of the nutrecess is disposed at the opposite side of the wrench recess. For apolygonal nut, the wrench recess is shaped to receive and provideclearance for a corner of the nut which is included in the peripheralportion embraced by the wrench recess. The nut may be engaged by agenerally radial movement of the wrench toward the center of thenutaccompanied by an angular movement for engaging the tooth in the cornerof the nut recess. Both ends of the wrench are angularly related to eachother and to the central handle portion so that with either end of thewrench in engagement with the .nut, the longitudinal axis of the handleportion is directed toward the centralaxis of the nut.

Other and further object of the invention will become apparent from areading of the following specification taken in conjunction with theaccompanying drawing, in which:

Figure l is an elevational view of an embodiment of the invention.

Figure 2 is a side view, partly in section, of the embodiment shown inFigure 1 taken along the line 22 of Figure 1 looking in the direction ofthe arrows.

Figure 3 is an elevational view similar to Figure 1, showing the otherend of the wrench in engagement with the nut.

Figure 4 is a fragmentary elevational view showing ditferent positionsof said wrench when engaging or disengaging the special nut.

Referring to the drawing, there is shown a doubleended wrench designatedgenerally as 10. The wrench It) comprises an elongated central handleportion 11. A first nut engaging portion 12 is disposed at one end ofthe handle portion 11. A second nutengaging portion 13 is disposed atthe other end of the handle portion 11.

The second nut engaging portion 13 comprises a concavely curved outerend surface 14 adapted for engagement with the convexly curved innerside of any of the nut recesses. There is a sloping lateral surface onthe second nut engaging portion 13 which extends inwardly toward thehandle portion 11 from one end of the concave surface 14 and defineswith the concave surface 14, a tooth 15. The sloping lateral surfaceslopes at an angle for engagement with one of the flat convergent sidesof a nut recess with the concave end surface 14 in engagement with oneof the convexly curved inner surfaces of the nut as shown in Figure .3,the tooth 15 being engaged in an inner corner of the nut recess adjacentto the fiat side which is engaged by the sloping lateral surface.

There is a two-sided notch 16 formed in the lateral surface of thesecond nut engaging portion 13 of the wrench. A first one of the sidesof the notch 16 ex tends from the apex portion of the notch 16 the otherend of the concave surface ll4 remote from the tooth 15.

This .first side is curved to guide the tooth 15 into an inner corner ofthe nut recess as shown in Figure 4. This first side is also spaced fromthe sloping lateral surface adjacent the tooth 15 to substantially fillthe space between the outer ends of the convergent sides of the nutrecess for positively maintaining the tooth 1S engaged in the innercorner of the nut recess during turning of the nut by the wrench 10. Asecond side of the notch 16 extends laterally outwardly from the apex ofthe notch and defines a shoulder for abutting engagement with theperiphery of the nut as shown in Figure 3. In Figure 3, the second sideof the notch is flat and engages against a flat portion of the side of ahexagonal nut.

The first nut-engaging portion 12 of the wrench it? has a wrench recess17 formed therein which opens outwardly away from the handle portion 11.The wrench re cess 17 receives and provides clearance for a peripheralportion of the nut which extends between two adjacent ones of the nutrecesses. As shown in Figure l, the wrench recess 1'7 may embrace acorner of the nut which is disposed midway between two adjacent nutrecesses.

The wrench recess 17 has a sloping lateral surface which is adapted forengagement with the flat side of either of the two nut recesses which isadjacent to the embraced peripheral portion of the nut and this slopinglateral surface terminates in a tooth 18 for engagement in the corner atthe inner end of the engaged flat side of the nut recess as shown inFigure 1.

At the other side of the wrench recess 17, the nut engaging portion 12is shaped to form a leg which is adapted to enter the nut recess whichis adjacent to the other end of the embraced peripheral portion of thenut, with the tooth 18 engaged in the inner corner of the adjacent nutrecess as shown in Figure 1. The end of the leg terminates in a concaveend surface 19 which is shaped for abutting engagement with the convexinner side of the recess which the leg has entered. The leg is providedwith a lateral surface which engages against the edge of the embracedperipheral portion of the nut as shown in Figure l for positivelyholding the tooth 18 en gaged in the inner corner of the nut recessduring turning of the nut by the wrench 10.

In the embodiment illustrated, the wrench is shown in engagement with anut 29 which is of regular hexagonal configuration having a central axisof symmetry. The periphery of the nut 20 has a series of regularlyspaced outwardly opening three-sided nut recesses 21 formed therein.Each nut recess 21 comprises two opposed flat convergent sides theplanes of which, if outwardly extended would intersect in a line ofintersection spaced radially outwardly beyond the periphery of the nut.This line of intersection lies in a plane passing through the centralaxis of the nut and which also passes through the center of the recess.Moreover, from an inspection of the drawing, it can be seen that theinterior angle of intersection between these two extended planes will begreater than 30, thus providing a sufiicient amount of inward slope tothe flat sides of each nut recess to assure positive nut turningengagement of either of the wrench teeth 15 or 18 in an inner corner ofthe nut recess without danger of the tooth slipping out of the engagednut recess. The third or inner side of each nut recess 21 is convexlycurved and the center of curvature is located at the central axis ofsymmetry of the nut 20. The peripheral portion 22 of nut 20 which isadapted to be embraced in the wrench recess 17 comprises a corner of thenut which is located midway between two adjacent nut recesses.

The toothed end 13 of wrench may be applied to the nut 20 as illustratedin Figure 4, the successive positions thereof being shown in Figure 4,the tooth being progressively guided into engagement with the innercorner 23 of the nut recess 21 by the action of the curved surface ofnotch 16, the tooth 15 being positively held engaged in the inner recesscorner 23 as the flat shoulder which extends laterally from the apex ofnotch 16 comes into abutting engagement with the flat side of the nut20.

In operation, the nut may be turned progressively in the same direction30 degrees at a time by the alternate use of opposite ends of the wrench10.

While but one form of the invention has been shown and described herein,it will be apparent to those skilled in the art that many minormodifications may be made without departing from the spirit of theinvention or the scope of the appended claims.

What is claimed is:

1. A wrench for use with a regularly shaped nut having a central axis ofsymmetry, the periphery of said nut having a plurality of regularlyspaced outwardly opening three-sided nut recesses formed therein, eachnut recess having two opposed flat convergent sides the planes of which,it outwardly extended, would intersect each other in a line ofintersection which lies in a plane passing through said central axis andthrough the center of said nut recess, said line of intersection beingspaced radially outwardly beyond the periphery of said nut and theinterior angle of intersection between said extended planes beinggreater than 30 degrees, and each nut recess having an inner third sidewhich extends between the inner ends of said fiat sides and is ofconvexly curved shape of which the center of curvature is located atsaid central axis,

said wrench comprising: an elongated handle portion and a nut engagingportion disposed at one end of said handle portion, said nut engagingportion having a wrench recess formed therein which opens outwardly awayfrom said handle portion and is shaped to provide clearance forembracing the peripheral portion of said nut which extends between anytwo adjacent ones of said nut recesses, one side of said wrench recesshaving a sloping lateral surface adapted for engagement with the fiatside of either of said two nut recesses which is adjacent to one end ofsaid embraced peripheral portion and terminating at its outer end in atooth for engagement in the corner at the inner end of said engaged sideof said nut recess, said nut engaging wrench portion at the other sideof said wrench recess being shaped to form a leg adapted to enter thenut recess which is adjacent to the other end of said embracedperipheral portion with said tooth engaged in said corner and to bringthe end of said leg into abutting engagement with said inner third sideof the recess which said leg has entered, said leg having a lateralsurface at said other side of said wrench recess which engages againstthe edge of said embraced peripheral portion adjacent to said enterednut recess for positively holding said tooth engaged in said cornerduring turning of said nut by said wrench.

2. A wrench for use with a regularly shaped nut having a central axis ofsymmetry, the periphery of said nut having a plurality of regularlyspaced outwardly opening three-sided nut recesses formed therein, eachnut recess having two opposed fiat convergent sides the planes of which,if outwardly extended would intersect each other in a line ofintersection which lies in a plane passing through said central axis andthrough the center of said nut recess, said line of intersection beingspaced radially outwardly beyond the periphery of said nut and theinterior angle of intersection between said extended planes beinggreater than 30 degrees, and each nut recess having an inner third sidewhich extends between the inner ends of said fiat sides and is ofconvexly curved shape of which the center of curvature is located atsaid central axis, said wrench comprising: an elongated handle portionand a nut engaging portion disposed at one end of said handle portion,said nut engaging portion comprises a concavely curved outer end surfaceshaped for individual engagement with a portion of said convexly curvedinner third side of any of said nut recesses, a sloping lateral surfaceextending inwardly toward said handle portion from one end of saidconcave end surface-at an angle for engagement with one of saidconvergent sides of said nut recess with said concave end surface inengagement with said convex third side thereof, and defining with saidconcave end surface a tooth adapted for engagement with an inner cornerof said nut recess, said nut engaging portion having a two-sided notchformed therein at the side thereof opposite said tooth, said notchhaving an apex from which a first side of said notch extends to theother end of said concave end surface, said first side of said notchbeing curved and spaced from said sloping lateral surface tosubstantially fill the space between the outer ends of said convergentsides of said nut recess for guiding said tooth into engagement in andpositively maintaining said tooth engaged in said corner during theturning of said nut by said wrench, and the second side of said notchextending laterally outwardly from said apex to define a shoulder forabutting engagement with the periphery of said nut.

3. A double-ended wrench for use with a regularly shaped nut having acentral axis of symmetry, the periphery of said nut having a pluralityof regularly spaced outwardly opening three-sided nut recesses formedtherein, each nut recess having two opposed fiat convergent sides theplanes of which, if outwardly extended,

would intersect each other in a line of intersection which lies in aplane passing through said central axis and through the center of saidnut recess, said line of intersection being spaced radially outwardlybeyond the periphery of said nut and the interior angle of intersectionbetween said extended planes being greater than 30 degrees, and each nutrecess having an inner third side which extends between the inner endsof said flat sides and is of convexly curved shape of which the centerof curvature is located at said central axis, said wrench comprising: afirst nut engaging portion disposed at one end of said handle portion,said first nut engaging portion having a wrench recess formed thereinwhich opens outwardly away from said handle portion and is shaped toprovide clearance for embracing the peripheral portion of said nut whichextends between any two adjacent ones of said nut recesses, one side ofsaid wrench recess having a sloping lateral surface adapted forengagement with the fiat side of either of said two nut recesses whichis adjacent to one end of said embraced peripheral portion andterminating at its outer end in a tooth for engagement in the corneratthe inner end of said engaged side of said nut recess, said first nutengaging portion of said wrench at the other side of said wrench recessbeing shaped to form a leg adapted to enter the nut recess which isadjacent to the other end of said embraced peripheral portion with saidtooth engaged in said corner and to bring the end of said leg intoabutting engagement with said inner third side of the recess which saidleg has entered, said leg having a lateral surface at said other side ofsaid wrench recess which engages against the edge of said embracedperipheral portion adjacent to said entered nut recess for positivelyholding said tooth engaged in said corner during turning of said nut bysaid first nut engaging portion of said wrench; and a second nutengaging portion disposed at the other end of said handle portion, saidsecond nut engaging portion comprising a concavely curved outer endsurface shaped for individual engagement with a portion of said convexlycurved inner third side of any of said nut recesses, a sloping lateralsurface extending inwardly toward said handle portion from one end ofsaid concave end surface at an angle for engagement with one of saidconvergent sides of said nut recess with said concave end surface inengagement with said convex third side thereof, and defining with saidconcave end surface, a further tooth adapted for engagement with aninner corner of said nut recess, said second nut engaging portion havinga twosided notch formed therein at the side thereof opposite saidfurther tooth, said notch having an apex from which a first side of saidnotch extends to the other end of said concave end surface, said firstside of said notch being curved and spaced from said sloping lateralsurface to substantially fill the space between the outer ends of saidconvergent sides of said nut recesses for guiding said further toothinto engagement in and positively maintaining said further tooth engagedin said corner during the turning of said nut by said second nut engaging portion of said wrench, the second side of said notch extendinglaterally outwardly from said apex to define a shoulder for abuttingengagement with the periphery of said nut; said first and second nutengaging portions of said wrench being angularly related to each otherand to said handle portion so that when said nut is engaged by either ofsaid two nut engaging portions thereof, the longitudinal axis of saidhandle portion is directed toward said central axis of said nut, wherebysaid wrench may be used in a restricted space by the alternate use ofsaid two nut engaging portions.

4. A double-ended wrench according to claim 3, in which said nut is ofregular polygonal peripheral configuration, the corners of said nutbeing disposed midway between adjacent ones of said nut recesses,wherein said wrench recess of said first nut engaging portion is shapedto receive a corner of said nut, and in which said second side of saidnotch of said second nut engaging portion is flat and defines a fiatshoulder for abutting engagement with a side of said nut intermediateone of said recesses and the corner of said nut adjacent thereto.

References Cited in the file of this patent UNITED STATES PATENTS591,779 Hagstrom Oct. 12, 1897 1,752,074 Gagne Mar. 25, 1930 2,420,458Barker May 13, 1947 OTHER REFERENCES Snap-On catalog TR, page 49, May1951.

